Even the most conservative investor hopes to find that one stock that can make them millions. That’s why they look at the biotech sector. One “home run” drug or therapeutic to enter the market can send a stock soaring along with an investor’s portfolio. The problem is that many of these long-term biotech stock investments never pan out. 

On the other hand, many potentially high return biotech stocks are excellent buy and hold candidates. Some of these companies, particularly the small-cap stocks may be trading as penny stocks. That adds to the risk. But it also allows you to scale into a position over time while managing the amount of capital you put at risk.  

Another option when looking at long-term biotech stock investments is to look at a company’s pipeline. Knowing what areas the company is researching can give you an opportunity to get in on the ground floor of megatrends.  

With all that said, investing in biotech stock is not for the faint of heart. But there are opportunities that exist. Here are three biotech stocks – one small-cap, one mid-cap, and one large cap – that have the opportunity to make you a millionaire.  

IBio (IBIO)

With an $11.76  million market cap, iBio (NYSEMKT:IBIO) is among the smallest of the small-cap stocks. And with IBIO stock down 90% in the last 12 months, investors should go into this investment with their eyes wide open. The company has a proprietary platform, called Discovery Engine,  which uses artificial intelligence to revolutionize and accelerate the production of vaccines and antibody treatments.  

The company made headlines in 2020 when it briefly made noise in the race among biotech companies to develop a vaccine for Covid-19. After that fell through, however, investors were reminded that the company doesn’t have a single candidate in clinical trials.  

But that could be changing. On June 12, 2023, iBio announced a partnership with the National Institutes of Health. The research agreement will explore the potential of its AI-driven platform to develop a novel vaccine for Lassa fever.  

The risk for investors is that iBio is not only not profitable, it generates precious little revenue at this time. A share price of just 70 cents per share makes IBIO stock a classic definition of risk versus reward, but when you’re looking for long-term biotech stock investments with millionaire-making potential, you have to take some risks.  

CRISPR Therapeutics (CRSP)

The nature of investing in biotech stocks is that there’s no such as a sure thing. But the field of gene editing may come about as close as you can get. And with its proprietary CRISPR/Cas9 gene editing platform, CRISPR Therapeutics (NASDAQ:CRSP) is at the forefront of this emerging sector. 

In 2023, the company signed a licensing deal with Vertex Pharmaceuticals (NASDAQ:VRTX) to advance its Exa-Cel platform for transfusion-dependent beta thalassemia and severe sickle cell disease. CRISPR and Vertex recently announced positive results in pivotal trials. However, a more compelling reason to look at CRISPR Therapeutics as one of the top biotech stocks to hold may come from the company’s work in immuno-oncology.  

CRSP stock soared in 2021 along with many biotech stocks. But there’s been a sharp pullback since then. In fact, as of this writing, the mid-cap stock is trading below its pre-pandemic level. However, analyst sentiment is bullish and institutional ownership remains strong.  

Pfizer (PFE)

When it comes to long-term bio-tech stock investments, investors may not immediately think of large-cap stocks. And after the success of its Covid-19 vaccine, many investors may be overlooking the opportunity that exists with Pfizer (NYSE:PFE). That sentiment is clearly evident in the PFE stock price which is down 31% from its all-time high.  

However, savvy investors continue to look forward. And in the case of Pfizer, there’s one thing that immediately stands out. In March, Pfizer acquired Seagen (NASDAQ:SGEN) for $43 billion. At a time when the Biden administration is calling for a cancer moonshot, this acquisition will allow Pfizer to expand it’s portfolio of oncology drugs. In fact, Pfizer is forecasting that the company’s pipeline will growt by $10 billion by 2030 as a result of the acquisition.  

The larger story is that the company is a leader in mRNA technology and it’s staking out a leadership in the area of customizable medicine. These are two areas which are forecast to have explosive growth.  

And the icing on the cake is that Pfizer is objectively undervalued. The company has a forward P/E of just 11x earnings and you get a dividend with a current yield of 4.09%.  

On the date of publication, Chris Markoch had a long position in PFE. The opinions expressed in this article are those of the writer, subject to the InvestorPlace.com Publishing Guidelines.